Peculiarities of protein hydrolysis on the digestive-transport surfaces of the intestine of the Kittiwake Rissa Tridactyla and Alcataenia Larina (Cestoda, Dilepididae) parasitizing it

Research of the activity of proteolytic enzymes functioning on the digestive-transport surfaces of the intestine of infected and noninfected kittiwakes Rissa tridactyla and cestodes Alcataenia larina (Cestoda, Dilepididae) parasitizing it was conducted. The protease activities depending on the pH values in the intestine of gulls and tapeworms were determined. The dynamics of desorption of enzymes of protein hydrolysis from the surface of the cestodes A. larina and the kittiwake intestine was studied. It was shown that the tapeworm invasion activates the processes of membrane and cavitary digestion of birds. It was determined that the degree of influence of the dilepidid infection on protease activity was defined mainly by the intensity of the invasion.     

Effect of <Emphasis Type="Italic">Caryophyllaeus laticeps</Emphasis> (Cestoda,Caryophyllidea) upon activity of digestive enzymes in bream

The activities of the main digestive hydrolases were comparatively studied in bream infected and noninfected with cestodes Caryophyllaeus laticeps (Pallas, 1781). It was shown that enzyme activities are distributed in the fish intestine in an irregular manner; the gradient of protease and lipase activities along the gut is presented. Following the infection of bream by cestodes, the activities of the studied enzymes decreased and the percentages of activities of various proteinase subclasses changed. No relation between the distribution of worms along the intestine and the levels of activities of digestive hydrolases was revealed.     

Activity of digestive enzymes of thick-billed guillemot (<Emphasis Type="Italic">Uria lomvia</Emphasis>) and common guillemot (<Emphasis Type="Italic">U. aalge</Emphasis>) invaded by cestodes

Activities of digestive enzymes (proteases, carbohydrases, acid and alkaline phosphatases) are determined in intestinal mucosa of the thick-billed and common guillemots. Comparative analysis of the obtained results is performed for non-infested and for birds infested by cestodes. It has been established that at infestation by cestode Alcataenia armillaris (Cestoda: Tetrabothriidae), activities of carbohydrase and alkaline phosphatase in intestinal mucosa of the thick-billed guillemot decreases. Parasitizing of cestodes Tetrabothrius jaegerskieldi (Cestoda: Tetrabothriidae) in intestine induces a decrease of saccharase activity. There is studied kinetics of desorption of enzymes from digestive-transport surfaces of the bird intestine. Peculiarities of firmness of enzyme fixation are established on the surface of intestinal mucosa of invaded guillemots. According to the obtained data, a decrease of the carbohydrase activities in intestine of infested guillemots is likely to be due to absorption of a part of enzymes hydrolyzing carbohydrates on the surface of cestodes.     

The fine structure of frontal glands in adult cestodes

Kuperman B. I. & Davydov V. G. 1982. The fine structure of frontal glands in adult cestodes. International Journal for Parasitology12: 285–293. The localization and structure of frontal glands of adult cestodes of 20 species from 4 orders: Caryophyllidea, Pseudophyllidea, Proteocephalidea and Cyclophyllidea were studied by light and electron microscopy. In cestodes of various orders there was evidence of differences in the ultrastructure of secretory cells, in the character of the secretion, and in the method of its discharge. The localization of glands in most adult cestodes is in the scolex. In Cyatocephalus, Ligulidae, Bothriocephalus claviceps, they are distributed also in the anterior and middle part of the body. In the species Caryophylleus (C. laticeps) and Khawia sinensis a major gland complex previously not described was discovered. The glands of the cestodes investigated may be divided into three main groups by their structure, localization and functional role in ontogenesis: (1) penetration glands in oncospheres which develop into procercoids and plerocercoids; (2) glands of plerocercoids and adult cestodes which develop in the gut; (3) gland complexes in the representatives of the order Caryophyllidea. The secretion is usually discharged at the scolex region and less frequently on the lateral surface. Three different ways of discharging secretory material from the cestodes body are described.     

The intestinal helminths of small mammals in the Malaysian tropical rain forest: Patterns of parasitism with respect to host ecology

Helminths of the intestine, liver and bile-duct of 8 species of small mammal from 3 localities in Peninsular Malaysia are reported. The most abundant hosts, Rattus surifer, R. sabanus and Tupaia glis harbour 13, 12 and 10 species of helminth respectively. There is no marked depletion in the number of helminth species per host species in the island locality. Infections with spiruroids, Digenea and cestodes reflect the insectivorous habits of the hosts. Characteristic parasite faunas can be defined. Patterns of parasitism are discussed with respect to the possible nature of the host-parasite relationships.     

SEASONAL AND DEMOGRAPHICAL VARIATION IN INTESTINAL HELMINTH INFECTION OF GREYWING FRANCOLIN

Little, R.M., Verster, A. & Crowe, T.M. 1993. Seasonal and demographical variation in intestinal helminth infection of Greywing Francolin. Ostrich 64:178-181.

The proportion of the population carrying intestinal parasites (prevalence of infection) and the mean number of parasites per host within the host population (worm burden) for 312 Greywing Francolin Fran-colinus africanus were recorded on the Stormberg Plateau, eastern Cape Province, during April 1989-De-cember 1990. Most Greywing (86%) had helminths in their small intestine or caeca. Variation in levels of helminth infection (i.e. both prevalence and burdens) was independent of host sex. Nematodes were confined to the caeca where they were present in high numbers throughout the year with two peaks during June-August and November-January. The prevalence and worm burdens of nematodes were independent of host age Nematodes were more prevalent than cestodes. The prevalence and number of cestodes in the small intestine were highest during September-February and Faked during November-December. Levels of prevalence of cestodes were significantly higher in juvenile Greywing than in adults during the austral winter (May-July). The number of cestodes was consistently, but not significantly, higher in juveniles than in adults. Greywing body mass and population density were not significantly correlated with worm burdens.     

First identification of eggs of the Asian fish tapeworm Bothriocephalus acheilognathi (Cestoda: Bothriocephalidea) in human stool

We report the first case of egg isolation of the Asian fish tapeworm Bothriocephalus acheilognathi (Bothriocephalidea) from human stool. A male patient from Saint Laurent du Maroni (French Guiana) presenting abdominal pain was examined in France for the diagnosis of intestinal parasites. Diphyllobothrium-like eggs were observed in his stool. However, molecular phylogenetic analyses based on sequences of rDNA and COI genes showed that the eggs observed belong to a bothriocephalidean cestode B. acheilognathi. The adult life stages of B. acheilognathi cestodes are known as invasive parasites of a wide spectrum of fish; however, they have not been described to parasitize any mammals. This human infection seems to be accidental and represents a parasite passage through human intestine after the consumption of an infected fish host.     

A checklist of helminth parasites of Elasmobranchii in Mexico

A comprehensive and updated summary of the literature and unpublished records contained in scientific collections on the helminth parasites of the elasmobranchs from Mexico is herein presented for the first time. At present, the helminth fauna associated with Elasmobranchii recorded in Mexico is composed of 132 (110 named species and 22 not assigned to species), which belong to 70 genera included in 27 families (plus 4 incertae sedis families of cestodes). These data represent 7.2% of the worldwide species richness. Platyhelminthes is the most widely represented, with 128 taxa: 94 of cestodes, 22 of monogeneans and 12 of trematodes; Nematoda and Annelida: Hirudinea are represented by only 2 taxa each. These records come from 54 localities, pertaining to 15 states; Baja California Sur (17 sampled localities) and Baja California (10), are the states with the highest species richness: 72 and 54 species, respectively. Up to now, 48 elasmobranch species have been recorded as hosts of helminths in Mexico; so, approximately 82% of sharks and 67% of rays distributed in Mexican waters lack helminthological studies. The present list provides the host, distribution (with geographical coordinates), site of infection, accession number in scientific collections, and references for the parasites. A host-parasite list is also provided.     

Morphological and molecular identification of hymenolepidid cestodes in children and synanthropic rodents from rural Mexico

Hymenolepidid cestodes of synanthropic rodents represent a risk for public health. In order to describe the occurrence of hymenolepidids in children and the role of rodents as a potential source of infection, we conducted a morphological and molecular survey on cestodes in two rural villages from Yucatan, Mexico. One hundred and thirty-five stool samples from children (64 from Paraíso and 71 from Xkalakdzonot), 233 Mus musculus (159 from Paraíso and 74 from Xkalakdzonot) and 125 Rattus rattus (7 from Paraíso and 118 from Xkalakdzonot) were analyzed for the presence of cestodes. Three hymenolepidid species were identified morphologically: Hymenolepis nana in 7.8% of children from Paraíso, Hymenolepis microstoma in 4.4% of M. musculus from Paraíso and Hymenolepis diminuta in 15.3% of R. rattus from Xkalakdzonot. The molecular characterization and phylogenetic analysis based on mitochondrial cytochrome c subunit 1 (CO1) gene and ribosomal internal transcribed spacer 1 (ITS1) region, confirmed the identity of the three cestodes isolated from Yucatan. Phylogeny of the CO1 gene identified intraspecific genetic differences within H. nana ranging from 0 to 5%, in H. microstoma from 0 to 0.4%, and in H. diminuta ranged from 0 to 6.5% which suggests, the presence of complex species within H. nana and H. diminuta infecting humans and rodents, as reported by other authors. Based on the morphological and molecular results, and the epidemiological evidence, infections with H. nana suggest a non-zoonotic transmission; however, the presence of H. microstoma and H. diminuta in synanthropic rodents serve as a possible source for human infection.     

Echinobothrium harfordi sp. nov. (Cestoda: Diphyllidae) from Raja naevus in the North Sea and English Channel.

Echinobothrium harfordi sp. nov. from the spiral intestine of Raja naevus in British waters is described and illustrated. The species most closely resembles E. affine as both possess two groups of eleven large apical hooks, but can be distinguished by fewer peduncle spines and by characteristics of the eggs. The intensity of infection in individual hosts was generally low, and although the incidence of infection was high in rays less than 35 cm in length, this fell towards zero in larger rays. The cestode showed a marked affinity for the first two tiers of the spiral intestine.     

Two new species of Macrobothridium (Cestoda: Diphyllidea) from rhinobatid elasmobranchs in the Gulf of Gabès, Tunisia, with notes on the status of the genus.

As a result of an investigation of metazoan parasites of elasmobranch fishes in the Gulf of Gabès, Tunisia, we discovered 2 new species of diphyllidean cestodes. Macrobothridium euterpes n. sp. is described from the spiral intestine of Rhinobatos rhinobatos, and Macrobothridium syrtensis n. sp. from the spiral intestine of Rhinobatos cemiculus. Macrobothridium euterpes is distinguished from the only other species in the genus (Macrobothridium rhynchobati) by the number of rostellar hooks, size, genital pore position, vagina position, and ovary shape. Macrobothridium syrtensis is distinguished from M. rhynchobati by the hook morphology, testis number, and overall size, and from M. euterpes by the number of rostellar hooks, testis number, genital pore position, vagina position, and ovary shape. These are the first 2 species added to the genus since its establishment in 1989. A standardized formula for representing the number and arrangement of rostellar hooks in diphyllidean species is presented.     

Fatal infection with Taenia martis metacestodes in a ring-tailed lemur (Lemur catta) living in an Italian zoological garden

A case of fatal infection caused by larval forms of Taenia martis in a ring-tailed lemur (Lemur catta) living in the Rome zoological garden is described. The animal, living in a semi-natural pen with other 15 conspecific individuals and being fed with fresh fruit and vegetables, yoghurt and eggs, was transported to the Istituto Zooprofilattico of Rome for post-mortem examination. The anamnesis included, ten days before the death, apathy, lack of appetite, abdominal distension and diarrhoea. A severe exudative fibrinous-purulent peritonitis with numerous adhesions between the abdominal wall and the bowel loops was detected. After intestine removal, two free and viable, 4 cm long, whitish, leaf-like parasitic forms were pinpointed. Macroscopic examination of the two parasites allowed their identification as larval stages of cestodes, identified via molecular analysis as T. martis metacestodes. This report represents the first record of T. martis infection in the host species and in a zoological garden and for the pathological relevance of the infection.     

Alkaline and acid phosphatase in the intestines of rats infected with a virulent strain of Entamoeba histolytica and treated with emetine and Flagyl

The distribution patterns of alkaline phosphatase (EC 3.1.3.1) and acid phosphatase (EC 3.1.3.2) in the intestine of rats inoculated intracaecally with a virulent strain of Entamoeba histolytica and treated with emetine hydrochloride and metronidazole (Flagyl) were studied. The caecum and the large intestine showed a highly significant increase in alkaline phosphatase activity after amoebic inoculation, and the enhanced activity was lowered by emetine and Flagyl treatment. There was no significant increase in acid phosphatase activity either in the caecum and the large intestine or in the small intestine (ileocaecal end). Intracaecal inoculation of bacterial associates alone from E. histolytica cultures did not produce any significant change in the level of these enzymes in the intestine.     

Distribution patterns and microhabitat segregation in gastrointestinal helminths of Sorex shrews

We studied the distribution patterns and microhabitat use in gastrointestinal helminths of the shrews Sorex araneus and S. caecutiens in Finland. The distribution of species prevalences was bimodal, and in S. araneus the abundance (mean intensity) was positively associated with commonness (prevalence), as assumed by the core-satellite species hypothesis (Hanski 1982). However, the positive correlation between prevalence and intensity was observed only when the effects of helminth body size and taxonomic group (cestodes vs nematodes) on intensity were controlled for. The nematodes of the genus Longistriata occurred predictably as core species, whereas the identity of the core cestodes was more variable between host species and regions. Helminth body size and taxonomic group were not related to the degree of aggregation in shrew populations, but helminth body size seemed to explain the differences in the distribution patterns of helminths between shrews and voles. The core species did not show more segregation in microhabitat use than randomly selected species. In fact, the two core nematodes showed largely overlapping intestinal distributions. We conclude that linear intestinal space is not a key resource for shrew nematodes, but it may be for shrew cestodes.     

Diversification and species boundaries of Rhinebothrium (Cestoda; Rhinebothriidea) in South American freshwater stingrays (Batoidea; Potamotrygonidae)

Background

Neotropical freshwater stingrays (Batoidea: Potamotrygonidae) host a diverse parasite fauna, including cestodes. Both cestodes and their stingray hosts are marine-derived, but the taxonomy of this host/parasite system is poorly understood.

Methodology

Morphological and molecular (Cytochrome oxidase I) data were used to investigate diversity in freshwater lineages of the cestode genus Rhinebothrium Linton, 1890. Results were based on a phylogenetic hypothesis for 74 COI sequences and morphological analysis of over 400 specimens. Cestodes studied were obtained from 888 individual potamotrygonids, representing 14 recognized and 18 potentially undescribed species from most river systems of South America.

Results

Morphological species boundaries were based mainly on microthrix characters observed with scanning electron microscopy, and were supported by COI data. Four species were recognized, including two redescribed (Rhinebothrium copianullum and R. paratrygoni), and two newly described (R. brooksi n. sp. and R. fulbrighti n. sp.). Rhinebothrium paranaensis Menoret & Ivanov, 2009 is considered a junior synonym of R. paratrygoni because the morphological features of the two species overlap substantially. The diagnosis of Rhinebothrium Linton, 1890 is emended to accommodate the presence of marginal longitudinal septa observed in R. copianullum and R. brooksi n. sp. Patterns of host specificity and distribution ranged from use of few host species in few river basins, to use of as many as eight host species in multiple river basins.

Significance

The level of intra-specific morphological variation observed in features such as total length and number of proglottids is unparalleled among other elasmobranch cestodes. This is attributed to the large representation of host and biogeographical samples. It is unclear whether the intra-specific morphological variation observed is unique to this freshwater system. Nonetheless, caution is urged when using morphological discontinuities to delimit elasmobranch cestode species because the amount of variation encountered is highly dependent on sample size and/or biogeographical representation.     

Specific features of the numbers and structure of the population of Proteocephalus longicollis (Zeder 1800) (Cestoda: Proteocephalidea)—A mass parasite of whitefish Coregonus lavaretus L. under conditions of technogenic pollution of the water body

The numbers, age structure, and morphological variation of the cestode Proteocephalus longicollis from whitefish of a natural water body (Kamennoe Lake) and those of Kostomuksha Lake polluted with wastes of the mining industry (northern Karelia) have been studied. In the polluted water body, a high infestation of whitefish and domination of larval stages in the structure of the parasite population have been established. It is shown that under conditions of pollution, only one of the variations of scolex signs dominates in the structure of phenotypic diversity. The size indices of cestodes are reliably smaller as compared with cestodes from the natural water body. The data obtained indicate that technogenic pollution determines a decrease in the intrapopulation diversity of P. longiocollis, and a decrease in the values of morphometric characters indicates inhibition of the morphophysiological state of individuals.     

The role of the rock cod Notothenia coriiceps Richardson, 1844 in the life-cycle of Antarctic parasites

Fifty specimens of Notothenia coriiceps caught in Potter Cove, King George Island, were examined for ecto- and endoparasites. Of the 22 parasite species found, 18 were helminths, 2 were hirudineans and 2 were crustaceans. The isopod Aega antarctica and an unidentified hirudinean are reported for the first time from this fish host. Dominant parasites were the adults of Aspersentis megarhynchus, the invasive stage of Corynosoma spp. (cystacanth) and the adults of Macvicaria pennelli, with respective prevalences of infestation of 94, 76 and 74%. The preferred sites of infestation were the pylorus and intestine, where five different larval (nematodes and cestodes) and eight adult (digeneans and acanthocephalans) parasite species were found. No adult nematodes and cestodes were found and no parasites could be isolated from the musculature. The results of the present study are related to previous findings on the parasite fauna of N. coriiceps. The comparison implies a high parasite diversity in this benthic Antarctic fish species. Most parasites found appear to have a wide range of distribution within Antarctic waters together with a low host specificity. Besides its role as final host for several species of trematodes and acanthocephalans, N. coriiceps serves as transmitter of parasite larvae to piscivorous birds and seals. It is concluded that the parasite fauna in Antarctic fish species provides important insights into the different habitat use and trophic relationship of their fish hosts. Received: 11 September 1997 / Accepted: 12 January 1998     

Comparison between the trypanorhynchid cestode infections of Penaeus duorarum and Penaeus brasiliensis in Biscayne Bay,Florida

Penaeus brasiliensis and P. duorarum from Biscayne Bay, Florida, were both found to be infected with four species of trypanorhynchid cestode larvae: Parachristianella monomegacantha, P. heteromegacanthus, Prochristianella penaei, and Renibulbus penaeus. The two shrimp species contained the cestodes in significantly different proportions and female P. duorarum had different proportions of cestodes than males. Three linear regressions of cestode infection on host size were also significant. The incidence and intensity of infection is given for each species of shrimp and cestode. This is the first record of P. heteromegacanthus and R. penaeus infecting Penaeus duorarum and modifies earlier information of P. duorarum infections in the bay.     

Existence of serotonin and neuropeptides-immunoreactive endocrine cells in the small and large intestines of the mole-rats (Spalax leucodon)

The present study was conducted to clarify the regional distribution and relative frequency of endocrine cells secreting serotonin, substance P (SP), cholecystokinin-8 (CCK-8), vasoactive intestinal polypeptide (VIP) and neurotensin in the small and large intestine of the mole-rats (Spalax leucodon), by specific immunohistochemical methods. In the small and large intestine of mole-rats (Spalax leucodon), serotonin, SP and VIP were identified with various frequencies, but CCK-8 and neurotensin were not observed. Most of the IR cells in the small and large intestine were located in the intestinal crypt and epithelium however, they were more frequency in the intestinal crypt. Serotonin-IR cells were detected throughout the whole intestinal tract, predominantly in the duodenum and colon. SP-IR cells were demonstrated throughout the whole intestinal tract except for the ileum and rectum with highest frequencies in the cecum. VIP-IR cells were found in all parts of the small intestine except for the large intestine.In conclusion, the general distribution patterns and relative frequency of intestinal endocrine cells of the mole-rats (Spalax leucodon) was similar to those of some rodent species. However, some species-dependent unique distributions and frequencies characteristics of endocrine cells were also observed in the present study.